"Owner Of A Curvy Bass" (Pete's Mouradian build)

[robocorpse]

Mouradian CS74 inspired build!
UPDATE: it's finished!

July 12th 1984, I saw Yes at Wembley Arena. Chris Squire (R.I.P.) pulled out a bizarre green thing to do "Make it Easy" and "Owner Of A Lonely heart" and I fell in love on sight. I spent ages trying to find out what it was, and after a few false leads, I found out it was a custom instrument, built by Jim Mouradian in Boston USA. Ever since then, this has been a total bucket list bass for me. However, seeing as Jim only made 25 of them and they sell for thousands of Dollars/Pounds on the very rare occasion they turn up used, there was no way I would be able to get my hands on one, even to just look over. So after years of thinking about it, the planets aligned and I decided to build my own CS74, or as close as I could get within my capabilities.

This has been on my mind for 33 years, I spent about 2 months planning and making the templates and about 3 weeks of evenings making the body. Taking it nice and slow as this is the first build I have done in about 20 years!

Caveat: I'm not very good at making necks, so I used one of my favourite comfy Jackson necks for this project and did it as a bolt-on. I might possibly have a crack at a neck thru version further down the line when I have had some more carving practice.

OK, here's the build diary!
So, with there only being 25 in the world, all I had to work from was photos. This was a mammoth task in itself and I probably spent more time in Photoshop lining up various photos, changing the perspective, comparing outlines and tweaking it until it was "just right", then sizing it all using 34" scale as a reference point until I had 17" between 12th fret and the approximate bridge saddle line. I ended up basing the main portion on a screen grab from the Chris Squire "Hot Licks" VHS.

While doing this, I realised that all the Mouradians I had photos of were slightly different, so I thought it was logical that they were probably all the same template, but the edge roundovers, pickup angles and control layouts were where most of the differences were. Chris Squire's CS74 (#3/25) has fairly plain edges so this was a relief, as a couple I saw were really tricky. His also had straight pickups rather than the angled ones on many others. More on this later...

So after 3 attempts and mockups, I ended up resizing the original to 97%, I still think this might have been slightly too big and I should have done it at 95%, but it works. I had to do a LOT of messing about with the top horn though as I was using a 24 fret neck, and Chris's bass joins at the 16th, this meant I had to reshape the top horn a little to accomodate the heel on the bolt-on, but I think I did a sympathetic modification here and kept the flow of the curves from strap button to bottom horn. I flowed it round and designed a heel bump into it so I could get as much body contact as possible with the heel without losing any curves.

I made up a template based on the heel of the Jackson neck, made some reference marks on the body template and carefully overlaid it into position before clamping it, and sinking holes through on the pillar drill in the pickup locations. This way, I could screw the template to the blank instead of double sided tape, and I could use those holes as reference points for when I screwed the neck template on so it would be dead on. Those holes would of course disappear when I routed the pickup cavities.

I decided on Poplar for the body to keep the weight down, the top strap button overhangs a long way, so balance wasn't going to be an issue here. I ordered a blank 38mm thick then jointed and glued it up with Titebond. After 24 hours, I gently released the pressure and left it overnight to be on the safe side. I planed the back and front as flat as I could, drew the centre line on over the join then screwed the template down, drew round it, then removed it and got busy with the bandsaw.

First major step done, I had a rough cut body. Looked good! I screwed the body template back on and routed the sides down in several passes using a couple of template follower bits, starting with a 12mm depth to get past the template without hogging too much wood (I should have made the template thicker on reflection) then when that bottomed out, I switched to a 25mm and finished off by removing the template and using the existing cut edge as the guide. I had a minor disaster on the second cut, the router clamp wasn't down all the way and it slipped upwards when I was doing the bottom bout, taking a strip off the template as well. I sanded a body offcut and made up some filler using the dust mixed with Titebond to fill the area, then sanded it back and matched it against the template. It will be invisible once the paint is on.

Next up, I screwed the neck template on, double checked it was all square with the centre line and carefully drilled the 2 bottom radius holes with a 5mm drillbit as this was closest to the neck heel corner radius. Then I hogged out the pocket with a Forstner bit. I started with 12mm for the corner areas but couldn't be bothered to change up to a 25mm, so I did the lot with the 12mm with the depth stop set so the Forstner tip would finish just shy of the intended 15mm depth and keep a clean bottom on the pocket once routed. Then in again with the router to get the sides done, then very carefully kissing away at the top so I didn't blow out the curve. Once that was done, I got stuck in and took the whole lot down to 15mm depth.

Next up, I copied the control locations from the photo and jiggled them a tiny bit, taking into account I would be using an oval jackplate, not a barrel jack (I hate those damn things!) and adding a preamp into the cavity. I also worked out the locations for the neck bolts and drew it up so I had room to use recessed washers and machine screws to fit the neck using inserts rather than old school screws, then drilled pilot holes into the body.

Test fit, snug as a bug in a rug, and passed the "wave it around without any bolts holding the neck on" test with flying colours (or in this case, "not flying" )

The next job was to plug the existing holes in the Jackson neck. Fairly straightforward, I used a plug cutter in an offcut of the Poplar, drilled matching holes into the existing screw holes on the pillar drill then tapped them in with some glue and left it to set overnight.

I chiselled off the excess of the plugs and scraped the remains down with a burred razor blade then carefully refitted it into the neck pocket and did a centre line test fit by rigging up some string through the bridge, anchored on a baseplate under the bass and fed through 2 tuners. Dead on!. Then came the nerve-testing job of drilling the neck for the inserts and fitting them, as this is pretty much a one-shot job, mess it up and it's more plugging and potentially weakening the heel when you redrill. I bored the holes in the pillar drill, then mounted a 4mm allen bit into the chuck and turned it by hand back and forward like a tap and die to get them in straight, with the neck clamped to the drill platform and a couple of little spacers underneath to keep the neck from tilting due to the radius. Heart in mouth, I tried bolting the neck on. Perfect first time. PHEW!
Once this was done, I gave the frets a level, crown and polish as this was a used neck and there was a bit of wear on the lower frets.

I searched high and low for some (affordable) narrow soapbar pickups for this bass. I was originally going to use EMG35s but decided I'd prefer to keep the skinny pickups like the CS74. This left me with a problem, so after a bit of thinking, I decided to make my own. Resin would be too messy and I'd have to make a master then clone it. I ended up designing covers to the size I reckoned the CS74 pickups were in a CAD program, then I measured up the bobbins on some Seymour Duncan Jazz pickups and made it all fit. I got a mate to 3D print me a prototype and after a bit of filing, I made it all fit. Quick redesign and another print, and I had a pair of CS74 looking covers with the 3 screw fixing that I could slot a Jazz bass bobbin into! They need sanding and finishing yet, but they look right in principle. I gave up trying to find M3 cap screws long enough to mount them, so I ended up using P90 screws as I didn't have quite enough room to install inserts in the bottom of the cavities to accept machine screws.
I made up a template for these and test routed some scrap to check the fit before attacking the actual body. I drilled the corner holes at 6mm to get the radius, used a Forstner bit to hog out the majority of the wood, then routed them out to 20mm and finished off the little corner nibs with a chisel.

Next up was marking out the control cavity lip. I fixed a lump of MDF to the body template on the bottom half and transferred the control locations through with a long 2mm drillbit. I removed it and used a 40mm holesaw on each hole, then joined the edge lines up and freehand routed the template to shape, finishing off with a flat file to get it clean. I made up a cavity plate using a lump of 3mm black plastic I found in a skip and got it mostly fitted, I'll finish that off when the paint is on to get a perfect fit.

I routed the edge of the lip to 3mm depth then took a 30mm Forstner bit and used the 2mm holes from earlier as pilot holes to sink the pot cavities so I would get a nice shape inside the cavity. The 30mm bit would give adequate clearance for 24mm pots. I drilled down to about 10mm from the face, then reattached the lip template and superglued a 10mm piece on the edge where the preamp was going, and 18mm on the other flat edges then carefully routed the 30mm edges off nice and uniform, before removing it and freehanding the rest of the interior.

Next up was routing for the Gotoh battery box, this was a simple template job and I lined it up so I could send the wires through the bridge pickup cavity, rather than trying to drill their own hole, which would have been a real pain given the steep angle. I then drilled the connecting holes for the pickups from inside the control cavity with a 6mm bit, and the earth wire for the bridge with a long 3mm bit.

Time to round the body over, not forgetting to mark a centre line for the output jack first.
I marked out where the edges would be smaller or larger radius (based on a few photos of the Green machine), then did the whole body with a 1/4" radius, then 3/8" on the larger sweeps and the neck joint, and will be adding 1/2" in a couple of places as well as cutting in a forearm curve as I always seem to end up with raw wrists if I don't have one.

The "hook" areas on the sides presented a problem. I didn't know how wide the gaps were on the original, and the template I made left a gap about 9mm wide that the bearing on my roundover bit wouldn't get through, so I routed right up to the edge, then took out the lump with a chisel then pared it down with a file and some 120 grit until it flowed into the rounded over parts.

Last job was to drill the hole for the output jack and the control holes.

Then sanding, lots of sanding!

I sanded to 150 grit, finished the forearm bit and mended a couple of little nicks inside the (bloody difficult annoying and "gah why did I decide to build a bloody CS74") side hooks.

I did a dry-run full assembly (minus electronics) and after a quick setup, it played really nicely and was very resonant and edgy. Of course, the first thing I banged out on this was "Owner Of A Lonely Heart"... it would have been rude not to

I located the correct Schaller 3-D4 bridge, what I believe are the correct skirted black aluminium knobs and 3PDT flat paddle toggle switch etc etc. I reasoned that though I had to make a massive concession by modifying the top horn to fit the Jackson neck, I'd do my best to match everything else, including copying the Barden soapbar pickups. I am undecided whether to add a string retainer behind the nut, because it is unnecessary on this neck, and won't show up against the black headstock, which I am leaving intact. The next task is to get it all finalised and sanded to 240 and double checked for any lumps or nicks, then I have to paint it. I am still in two minds whether to DIY or get it done pro, I have been quoted lots of money for the CS green finish because it is a sod to sand and polish, and 2 finishers have declined the work. This really would be a test of my finishing skills, and, well, lets see. I am really pleased with the way this has come out..

R.I.P. Chris Squire, my favourite bassist of all time.

Edited December 2, 2017 by robocorpse
Updated image

[Andyjr1515]

I'll have a proper look at this when I'm back on a proper PC this eve, but from my phone it looks excellent. I built one for our very own gelfin last year and now have a bit of a soft spot for them

[Jakester]

You wait ages for a Mouradian to come along and then two come at once!

[cheddatom]

nice one!

[gelfin]

Some pis of the CS that Andyjr1515 built for me earlier this year.


[url="https://postimg.org/image/kd5yob9dr/"][/url]

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Showing how we hid the Smoothound transmitter.

[url="https://postimage.org"][/url]

Full build thread here. [url="http://basschat.co.uk/topic/294432-finished-and-now-for-something-completely-different/"]http://basschat.co.u...tely-different/[/url]

Also I believe that there were only six of the original built by Jim Mouradian. Others by his son, Ed Roman guitars and Washburn.

Edited July 27, 2017 by gelfin

[SpondonBassed]

That's very nice. I mean [i]where's my wallet[/i] kinda nice.

[scojack]

Great job robo, look forward to seeing it painted

[Norris]

Excellent work! That's going to look lovely

[Norris]

Gah! Double post!

Edited July 29, 2017 by Norris

[gelfin]

Altough I did get Andy to build one for me I did have a go myself a few years ago. But I did get carried away with the design. Also my son wanted his own guitar version.

[url=https://postimg.org/image/5g4dpwy7z/][/url]

[gelfin]

Just wondering how this build is going ?

[robocorpse]

Not much further since last post, festival season upon us and I have been flat out! I've decided to let someone else do the finishing so I am doing a bit more profiling and adding an arm contour, sanding it down to 240 then leaving it in the hands of a pro for the paint job, there is no way I could get it nice enough with rattlecans and I don't have access to compressor or spraybooth! With luck, I'll report back in a few weeks with totally finished photos

[robocorpse]

Sorry for the delay, had a lot on my plate. IT'S COMPLETE!

I had to choose between a solid finish (myself) or splashing out on getting the "Green Machine" pearl candy with the stripe. So I bit the bullet and got Rob at Knight Guitars to do the paint for me.  The photos don't show the beautiful depth and shimmer of the pearl candy, I couldn't get the light right, but it flipflops through differing shades of deep green through to lime.

The bass is assembled, plays beautifully and sounds nice and throaty with plenty of zing due to the Jazz positioning and high output Seymours hidden under the custom covers.

Here is the finished article, hope you like it.

 

[ezbass]

Very nice result; enjoy.

[TheGreek]

Another member of the BC Mouradian-ish Owners club.

Nice bass...expect lots of "what's that then" questions from Fender owners.

[Andyjr1515]

Lovely job   Top drawer stuff...

[Norris]

Beautiful! 

[cheddatom]

brilliant!

[Oopsdabassist]

Beautiful job, and I LOVE that green finish, play it lots and wait for the comments from the crowd!!!

[robocorpse]

Took it out on 3 gigs at the weekend. It sounds absolutely monster, like a Jazz bass on steroids!

Now it has passed the acid test and I know what I'd do differently next time, I have decided there will definitely be a "next time" and I am mulling over what bass to build next when I have finished the Tele I'm mucking about with. I am very tempted to build another one of these and really mess with it

[roman_sub]

Great job. I personally prefer the pickup position you have gone with, as compared to original. Glad it sounds killer and you completed your objective!